(i) Technical Field
The present invention relates to a semiconductor device, and more particularly, to a semiconductor device having a structure in which an electrode and a protective film are provided on or above a semiconductor layer.
(ii) Related Art
A protective film composed of an insulating material such as a silicon nitride (SiN) may be provided on the surface of a semiconductor layer to protect the semiconductor layer of a semiconductor device from stress and fouling.
There is a proposal to provide a ball of a bonding wire on an insulative cover film on a pad electrode to thus improve the degree of adhesion of the bonding wire and to prevent moisture penetration (see Japanese Laid-Open Patent Publication No. 5-136197).
In this proposal, if the ball and the insulative cover film does not have good coverage, a gap may be developed therebetween and moisture may penetrate therethrough. The moisture penetration may degrade the long-term reliability and corrode the pad electrode. This may result in exfoliation of the insulative film. When the ball is attached to the pad electrode with pressure, a crack may occur in the insulative cover film.